1. Field of the Invention
The present invention relates to the field of Multi-media Broadcast/Multicast Services (MBMS). More particularly, the present invention relates to providing MBMS data to user equipment in a Multi-media Broadcast over a Single Frequency Network area.
2. Description of the Related Art
In a Multi-media Broadcast over a Single Frequency Network (MBSFN), Multi-media Broadcast/Multicast Services (MBMS) provide simultaneous delivery of multimedia content (e.g., television content, films, news content) to a large set of user equipment in an MBSFN area via a group of cells. The multi-media broadcast services can be received by any subscriber (e.g., user equipment) located in the MBSFN area in which the service is offered while the multi-media multicast services can only be received by user equipment having subscribed to the MBMS and having joined the multicast group associated with the MBMS. Both services are unidirectional point-to-multipoint transmissions of MBMS data and can be applied to broadcast text, audio, picture, video from Broadcast Multicast Service Centre (BM-SC) to any user located in the service area.
Typically, a group of cells in the MBSFN area are configured to provide MBMS data to user equipment in a time synchronized manner. The group of cells has the same frequency band allocated with contiguous coverage such that the cells are able to be synchronized and have the capability of transmitting MBMS data in a single frequency network mode.
In E-UTRAN, also known as Long Term Evolution (LTE), self backhauling is a relaying technique in which a wireless base station is wirelessly connected to the remaining part of a network via another cell which is controlled by an evolved Node B (eNB), commonly known as Donor eNB (DeNB). A wireless base station (also known as a relay node) may constitute one or more cell of its own or may be used to extend cells covered by the DeNB.
The self-backhauling concept implies that the link between the donor eNB and the relay node can operate in the same frequency spectrum, i.e. frequency-overlapped with the radio access links that provide access for User Equipment (UEs) within the donor cell and the UEs within the cell(s) controlled by the relay node. Typically, the radio technology used for the self-backhaul link is similar to the one used within the donor cell and the cell(s) of the relay node respectively. For example, when the donor eNB and the relay node use the LTE radio access technology for communicating with UEs within their cell(s), the self-backhaul link should also be LTE-based or at least based on an LTE-like radio technology.
Multiple such relay nodes may be employed under a single DeNB to extend cells covered by the DeNB. The relay nodes associated with the DeNB may be a part of an MBSFN area that includes eNBs and DeNBs. Alternatively, the relay nodes associated with the DeNB can be a part of separate MBSFN area as illustrated in FIG. 1.
FIG. 1 is a schematic diagram illustrating an MBSFN environment in which relay nodes are part of separate MBSFN area according to the related art.
Referring to FIG. 1, currently, none of the relay nodes are used for synchronized transmission of MBMS data to its UEs along the eNBs and the DeNBs in an MBSFN area. This is due to the fact that an MBMS Control Entity (MCE) (e.g., entity responsible for allocation of time and frequency resources for MBMS data transmission) is not connected to the relay nodes in the existing 3GPP architecture and the DeNB associated with the relay nodes does not have appropriate capabilities to provide the MBMS data to user equipment connected through relay nodes in a synchronized manner.
The above information is presented as background information only to assist with an understanding of the present disclosure. No determination has been made, and no assertion is made, as to whether any of the above might be applicable as prior art with regard to the present invention.